fittings?

barb fittings ...never had any leaks since i switched..

All Parker prestoloc, all brass but I never use that factory red teflon, I like traditional white teflon wrap. Never had a fitting leak yet.

We use the Alkon D.O.T. Aprov. Really any brass D.O.T. approved fitting should do you good.

The standard push-pull fittings. some work better then others however i would suggest against it, i the line isnt comming out straight then they will leak

Compressons dont leak but you have to replace the inside of the fitting if you want to reuse them

Pushloc barbs are great for high pressure, but they are a one time use fitting. if you cut off the airline they will keep blowing on the new line if you sore the fitting (always do)